The human lymphatic system has the task of removing all substances from the connective tissue which cannot be removed by the blood vessel system (so-called obligatory lymph load). Without a functioning lymphatic system, humans are not viable.
In this second part about the human lymphatic system you will learn which organs make up the lymphatic system.
The lymphatic system
Humans possess 4 different tonsil species (t. pharyngea, t.palatina, t. lingualis and t. tubaria) They are located in the area of mouth, palate and throat. Together they form the so-called “lymphatic pharyngeal ring”. Their function is to protect the upper respiratory tract from harmful organisms such as bacteria, viruses or fungi from the oral and nasal cavities.
The spleen is integrated in the blood circulation and lies in the abdominal cavity to the left of the stomach. The spleen has three important functions:
- proliferation of lymphocytes, which belong to the white blood cells (leukocytes) and form part of the immune system.
- Storage site of monocytes, which also belong to the white blood cells (leukocytes). They are also part of the immune system.
- exclusion of obsolete and defective red blood cells (erythrocytes).
Lymphocytes, monocytes and erythrocytes are all components of human blood.
The thymus is a two lobed organ which lies behind the breastbone. The thymus loses its function with the onset of puberty. Until then, it serves the primary development of T lymphocytes against specific antigens.
Lymphatic Tissue (MALT)
MALT (Mucosa Associated Lymphoid Tissue) is the term used to describe knot-like accumulations of lymphocytes under the mucous membranes of various organs. For example, under the bronchial mucosa (BALT), under the mucous membranes of the gastrointestinal tract (GALT), or under the vaginal mucosa (VALT).
Lymphatic Vascular System
- Lymph capillaries and pre-collectors ⇒ initial lymph vessels for the absorption (resorption) of the lymphatic load.
- Collectors and lymphatic strains ⇒ Transport of lymph into the blood system.
A collector is a section of a vessel between two directional flaps whose wall shows the typical three-layer structure:
- Media (from smooth muscle cells, thereby lymphangiomotoric / lymphvasomotoric responds to stretching with contraction)
Pre-collectors can have both resorbing and evacuating capabilities.
|lymphatic vascular system parts with respect to their spread (from small to large)|
|skin area||lymph capillaries|
|Hautterritorium (Here the
|Collectors, lymph nodes|
|surface lymphatic system||drain skin and subcutis, lies above the muscle fascia|
|deep lymphatic system||lying in the fascia (epi/intrafascial) drains muscles, periosteum, tendons, ligaments, and nerves|
prelymphatic tissue clefts
Prelymphatic tissue clefts are microscopically small and ensure that fluid from the blood capillary reaches the cells.
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